LibCrypto: Move all elliptic curve private methods into .cpp

All the elliptic curve implementations had a long list of private
methods which were all stored in a single .cpp file. Now we simply use
static methods instead.

Userland/Libraries/LibCrypto/Curves/SECP256r1.cpp

@@ -14,6 +14,14 @@
 
 namespace Crypto::Curves {
 
+static constexpr u256 REDUCE_PRIME { u128 { 0x0000000000000001ull, 0xffffffff00000000ull }, u128 { 0xffffffffffffffffull, 0x00000000fffffffe } };
+static constexpr u256 REDUCE_ORDER { u128 { 0x0c46353d039cdaafull, 0x4319055258e8617bull }, u128 { 0x0000000000000000ull, 0x00000000ffffffff } };
+static constexpr u256 PRIME_INVERSE_MOD_R { u128 { 0x0000000000000001ull, 0x0000000100000000ull }, u128 { 0x0000000000000000ull, 0xffffffff00000002ull } };
+static constexpr u256 PRIME { u128 { 0xffffffffffffffffull, 0x00000000ffffffffull }, u128 { 0x0000000000000000ull, 0xffffffff00000001ull } };
+static constexpr u256 R2_MOD_PRIME { u128 { 0x0000000000000003ull, 0xfffffffbffffffffull }, u128 { 0xfffffffffffffffeull, 0x00000004fffffffdull } };
+static constexpr u256 ONE { 1u };
+static constexpr u256 B_MONTGOMERY { u128 { 0xd89cdf6229c4bddfull, 0xacf005cd78843090ull }, u128 { 0xe5a220abf7212ed6ull, 0xdc30061d04874834ull } };
+
 static u256 import_big_endian(ReadonlyBytes data)
 {
     VERIFY(data.size() == 32);
@@ -53,7 +61,7 @@ static u512 multiply(u256 const& left, u256 const& right)
     return { result.low, result.high };
 }
 
-u256 SECP256r1::modular_reduce(u256 const& value)
+static u256 modular_reduce(u256 const& value)
 {
     // Add -prime % 2^256 = 2^224-2^192-2^96+1
     bool carry = false;
@@ -63,7 +71,7 @@ u256 SECP256r1::modular_reduce(u256 const& value)
     return select(value, other, carry);
 }
 
-u256 SECP256r1::modular_reduce_order(u256 const& value)
+static u256 modular_reduce_order(u256 const& value)
 {
     // Add -order % 2^256
     bool carry = false;
@@ -73,7 +81,7 @@ u256 SECP256r1::modular_reduce_order(u256 const& value)
     return select(value, other, carry);
 }
 
-u256 SECP256r1::modular_add(u256 const& left, u256 const& right, bool carry_in)
+static u256 modular_add(u256 const& left, u256 const& right, bool carry_in = false)
 {
     bool carry = carry_in;
     u256 output = left.addc(right, carry);
@@ -90,7 +98,7 @@ u256 SECP256r1::modular_add(u256 const& left, u256 const& right, bool carry_in)
     return output + addend;
 }
 
-u256 SECP256r1::modular_sub(u256 const& left, u256 const& right)
+static u256 modular_sub(u256 const& left, u256 const& right)
 {
     bool borrow = false;
     u256 output = left.subc(right, borrow);
@@ -107,7 +115,7 @@ u256 SECP256r1::modular_sub(u256 const& left, u256 const& right)
     return output - sub;
 }
 
-u256 SECP256r1::modular_multiply(u256 const& left, u256 const& right)
+static u256 modular_multiply(u256 const& left, u256 const& right)
 {
     // Modular multiplication using the Montgomery method: https://en.wikipedia.org/wiki/Montgomery_modular_multiplication
     // This requires that the inputs to this function are in Montgomery form.
@@ -129,22 +137,22 @@ u256 SECP256r1::modular_multiply(u256 const& left, u256 const& right)
     return modular_add(mult.high(), mp.high(), carry);
 }
 
-u256 SECP256r1::modular_square(u256 const& value)
+static u256 modular_square(u256 const& value)
 {
     return modular_multiply(value, value);
 }
 
-u256 SECP256r1::to_montgomery(u256 const& value)
+static u256 to_montgomery(u256 const& value)
 {
     return modular_multiply(value, R2_MOD_PRIME);
 }
 
-u256 SECP256r1::from_montgomery(u256 const& value)
+static u256 from_montgomery(u256 const& value)
 {
     return modular_multiply(value, ONE);
 }
 
-u256 SECP256r1::modular_inverse(u256 const& value)
+static u256 modular_inverse(u256 const& value)
 {
     // Modular inverse modulo the curve prime can be computed using Fermat's little theorem: a^(p-2) mod p = a^-1 mod p.
     // Calculating a^(p-2) mod p can be done using the square-and-multiply exponentiation method, as p-2 is constant.
@@ -193,7 +201,7 @@ u256 SECP256r1::modular_inverse(u256 const& value)
     return result;
 }
 
-void SECP256r1::point_double(JacobianPoint& output_point, JacobianPoint const& point)
+static void point_double(JacobianPoint& output_point, JacobianPoint const& point)
 {
     // Based on "Point Doubling" from http://point-at-infinity.org/ecc/Prime_Curve_Jacobian_Coordinates.html
 
@@ -247,7 +255,7 @@ void SECP256r1::point_double(JacobianPoint& output_point, JacobianPoint const& p
     output_point.z = zp;
 }
 
-void SECP256r1::point_add(JacobianPoint& output_point, JacobianPoint const& point_a, JacobianPoint const& point_b)
+static void point_add(JacobianPoint& output_point, JacobianPoint const& point_a, JacobianPoint const& point_b)
 {
     // Based on "Point Addition" from  http://point-at-infinity.org/ecc/Prime_Curve_Jacobian_Coordinates.html
     if (point_a.x.is_zero_constant_time() && point_a.y.is_zero_constant_time() && point_a.z.is_zero_constant_time()) {
@@ -314,7 +322,7 @@ void SECP256r1::point_add(JacobianPoint& output_point, JacobianPoint const& poin
     output_point.z = z3;
 }
 
-void SECP256r1::convert_jacobian_to_affine(JacobianPoint& point)
+static void convert_jacobian_to_affine(JacobianPoint& point)
 {
     u256 temp;
     // X' = X/Z^2
@@ -328,7 +336,7 @@ void SECP256r1::convert_jacobian_to_affine(JacobianPoint& point)
     point.y = modular_multiply(point.y, temp);
 }
 
-bool SECP256r1::is_point_on_curve(JacobianPoint const& point)
+static bool is_point_on_curve(JacobianPoint const& point)
 {
     // This check requires the point to be in Montgomery form, with Z=1
     u256 temp, temp2;

Userland/Libraries/LibCrypto/Curves/SECP256r1.h

@@ -25,29 +25,6 @@ public:
     ErrorOr<ByteBuffer> generate_public_key(ReadonlyBytes a) override;
     ErrorOr<ByteBuffer> compute_coordinate(ReadonlyBytes scalar_bytes, ReadonlyBytes point_bytes) override;
     ErrorOr<ByteBuffer> derive_premaster_key(ReadonlyBytes shared_point) override;
-
-private:
-    static u256 modular_reduce(u256 const& value);
-    static u256 modular_reduce_order(u256 const& value);
-    static u256 modular_add(u256 const& left, u256 const& right, bool carry_in = false);
-    static u256 modular_sub(u256 const& left, u256 const& right);
-    static u256 modular_multiply(u256 const& left, u256 const& right);
-    static u256 modular_square(u256 const& value);
-    static u256 to_montgomery(u256 const& value);
-    static u256 from_montgomery(u256 const& value);
-    static u256 modular_inverse(u256 const& value);
-    static void point_double(JacobianPoint& output_point, JacobianPoint const& point);
-    static void point_add(JacobianPoint& output_point, JacobianPoint const& point_a, JacobianPoint const& point_b);
-    static void convert_jacobian_to_affine(JacobianPoint& point);
-    static bool is_point_on_curve(JacobianPoint const& point);
-
-    static constexpr u256 REDUCE_PRIME { u128 { 0x0000000000000001ull, 0xffffffff00000000ull }, u128 { 0xffffffffffffffffull, 0x00000000fffffffe } };
-    static constexpr u256 REDUCE_ORDER { u128 { 0x0c46353d039cdaafull, 0x4319055258e8617bull }, u128 { 0x0000000000000000ull, 0x00000000ffffffff } };
-    static constexpr u256 PRIME_INVERSE_MOD_R { u128 { 0x0000000000000001ull, 0x0000000100000000ull }, u128 { 0x0000000000000000ull, 0xffffffff00000002ull } };
-    static constexpr u256 PRIME { u128 { 0xffffffffffffffffull, 0x00000000ffffffffull }, u128 { 0x0000000000000000ull, 0xffffffff00000001ull } };
-    static constexpr u256 R2_MOD_PRIME { u128 { 0x0000000000000003ull, 0xfffffffbffffffffull }, u128 { 0xfffffffffffffffeull, 0x00000004fffffffdull } };
-    static constexpr u256 ONE { 1u };
-    static constexpr u256 B_MONTGOMERY { u128 { 0xd89cdf6229c4bddfull, 0xacf005cd78843090ull }, u128 { 0xe5a220abf7212ed6ull, 0xdc30061d04874834ull } };
 };
 
 }

Userland/Libraries/LibCrypto/Curves/X25519.cpp

@@ -11,19 +11,24 @@
 
 namespace Crypto::Curves {
 
-void X25519::import_state(u32* state, ReadonlyBytes data)
+static constexpr u8 BITS = 255;
+static constexpr u8 BYTES = 32;
+static constexpr u8 WORDS = 8;
+static constexpr u32 A24 = 121666;
+
+static void import_state(u32* state, ReadonlyBytes data)
 {
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         u32 value = ByteReader::load32(data.offset_pointer(sizeof(u32) * i));
         state[i] = AK::convert_between_host_and_little_endian(value);
     }
 }
 
-ErrorOr<ByteBuffer> X25519::export_state(u32* data)
+static ErrorOr<ByteBuffer> export_state(u32* data)
 {
-    auto buffer = TRY(ByteBuffer::create_uninitialized(X25519::BYTES));
+    auto buffer = TRY(ByteBuffer::create_uninitialized(BYTES));
 
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         u32 value = AK::convert_between_host_and_little_endian(data[i]);
         ByteReader::store(buffer.offset_pointer(sizeof(u32) * i), value);
     }
@@ -31,49 +36,68 @@ ErrorOr<ByteBuffer> X25519::export_state(u32* data)
     return buffer;
 }
 
-void X25519::select(u32* state, u32* a, u32* b, u32 condition)
+static void select(u32* state, u32* a, u32* b, u32 condition)
 {
     // If B < (2^255 - 19) then R = B, else R = A
     u32 mask = condition - 1;
 
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         state[i] = (a[i] & mask) | (b[i] & ~mask);
     }
 }
 
-void X25519::set(u32* state, u32 value)
+static void set(u32* state, u32 value)
 {
     state[0] = value;
 
-    for (auto i = 1; i < X25519::WORDS; i++) {
+    for (auto i = 1; i < WORDS; i++) {
         state[i] = 0;
     }
 }
 
-void X25519::copy(u32* state, u32* value)
+static void copy(u32* state, u32* value)
 {
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         state[i] = value[i];
     }
 }
 
-void X25519::conditional_swap(u32* first, u32* second, u32 condition)
+static void conditional_swap(u32* first, u32* second, u32 condition)
 {
     u32 mask = ~condition + 1;
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         u32 temp = mask & (first[i] ^ second[i]);
         first[i] ^= temp;
         second[i] ^= temp;
     }
 }
 
-void X25519::modular_multiply_single(u32* state, u32* first, u32 second)
+static void modular_reduce(u32* state, u32* data)
+{
+    // R = A mod p
+    u64 temp = 19;
+    u32 other[WORDS];
+
+    for (auto i = 0; i < WORDS; i++) {
+        temp += data[i];
+        other[i] = temp & 0xFFFFFFFF;
+        temp >>= 32;
+    }
+
+    // Compute B = A - (2^255 - 19)
+    other[7] -= 0x80000000;
+
+    u32 mask = (other[7] & 0x80000000) >> 31;
+    select(state, other, data, mask);
+}
+
+static void modular_multiply_single(u32* state, u32* first, u32 second)
 {
     // Compute R = (A * B) mod p
     u64 temp = 0;
-    u32 output[X25519::WORDS];
+    u32 output[WORDS];
 
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += (u64)first[i] * second;
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
@@ -87,7 +111,7 @@ void X25519::modular_multiply_single(u32* state, u32* first, u32 second)
     output[7] &= 0x7FFFFFFF;
 
     // Fast modular reduction
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += output[i];
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
@@ -96,29 +120,23 @@ void X25519::modular_multiply_single(u32* state, u32* first, u32 second)
     modular_reduce(state, output);
 }
 
-void X25519::modular_square(u32* state, u32* value)
-{
-    // Compute R = (A ^ 2) mod p
-    modular_multiply(state, value, value);
-}
-
-void X25519::modular_multiply(u32* state, u32* first, u32* second)
+static void modular_multiply(u32* state, u32* first, u32* second)
 {
     // Compute R = (A * B) mod p
     u64 temp = 0;
     u64 carry = 0;
-    u32 output[X25519::WORDS * 2];
+    u32 output[WORDS * 2];
 
     // Comba's method
     for (auto i = 0; i < 16; i++) {
-        if (i < X25519::WORDS) {
+        if (i < WORDS) {
             for (auto j = 0; j <= i; j++) {
                 temp += (u64)first[j] * second[i - j];
                 carry += temp >> 32;
                 temp &= 0xFFFFFFFF;
             }
         } else {
-            for (auto j = i - 7; j < X25519::WORDS; j++) {
+            for (auto j = i - 7; j < WORDS; j++) {
                 temp += (u64)first[j] * second[i - j];
                 carry += temp >> 32;
                 temp &= 0xFFFFFFFF;
@@ -136,7 +154,7 @@ void X25519::modular_multiply(u32* state, u32* first, u32* second)
     output[7] &= 0x7FFFFFFF;
 
     // Fast modular reduction 1st pass
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += output[i];
         temp += (u64)output[i + 8] * 38;
         output[i] = temp & 0xFFFFFFFF;
@@ -151,7 +169,7 @@ void X25519::modular_multiply(u32* state, u32* first, u32* second)
     output[7] &= 0x7FFFFFFF;
 
     // Fast modular reduction 2nd pass
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += output[i];
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
@@ -160,11 +178,17 @@ void X25519::modular_multiply(u32* state, u32* first, u32* second)
     modular_reduce(state, output);
 }
 
-void X25519::modular_add(u32* state, u32* first, u32* second)
+static void modular_square(u32* state, u32* value)
+{
+    // Compute R = (A ^ 2) mod p
+    modular_multiply(state, value, value);
+}
+
+static void modular_add(u32* state, u32* first, u32* second)
 {
     // R = (A + B) mod p
     u64 temp = 0;
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += first[i];
         temp += second[i];
         state[i] = temp & 0xFFFFFFFF;
@@ -174,11 +198,11 @@ void X25519::modular_add(u32* state, u32* first, u32* second)
     modular_reduce(state, state);
 }
 
-void X25519::modular_subtract(u32* state, u32* first, u32* second)
+static void modular_subtract(u32* state, u32* first, u32* second)
 {
     // R = (A - B) mod p
     i64 temp = -19;
-    for (auto i = 0; i < X25519::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += first[i];
         temp -= second[i];
         state[i] = temp & 0xFFFFFFFF;
@@ -191,26 +215,7 @@ void X25519::modular_subtract(u32* state, u32* first, u32* second)
     modular_reduce(state, state);
 }
 
-void X25519::modular_reduce(u32* state, u32* data)
-{
-    // R = A mod p
-    u64 temp = 19;
-    u32 other[X25519::WORDS];
-
-    for (auto i = 0; i < X25519::WORDS; i++) {
-        temp += data[i];
-        other[i] = temp & 0xFFFFFFFF;
-        temp >>= 32;
-    }
-
-    // Compute B = A - (2^255 - 19)
-    other[7] -= 0x80000000;
-
-    u32 mask = (other[7] & 0x80000000) >> 31;
-    select(state, other, data, mask);
-}
-
-void X25519::to_power_of_2n(u32* state, u32* value, u8 n)
+static void to_power_of_2n(u32* state, u32* value, u8 n)
 {
     // compute R = (A ^ (2^n)) mod p
     modular_square(state, value);
@@ -219,11 +224,11 @@ void X25519::to_power_of_2n(u32* state, u32* value, u8 n)
     }
 }
 
-void X25519::modular_multiply_inverse(u32* state, u32* value)
+static void modular_multiply_inverse(u32* state, u32* value)
 {
     // Compute R = A^-1 mod p
-    u32 u[X25519::WORDS];
-    u32 v[X25519::WORDS];
+    u32 u[WORDS];
+    u32 v[WORDS];
 
     // Fermat's little theorem
     modular_square(u, value);
@@ -276,14 +281,14 @@ ErrorOr<ByteBuffer> X25519::generate_public_key(ReadonlyBytes a)
 // https://datatracker.ietf.org/doc/html/rfc7748#section-5
 ErrorOr<ByteBuffer> X25519::compute_coordinate(ReadonlyBytes input_k, ReadonlyBytes input_u)
 {
-    u32 k[X25519::WORDS] {};
-    u32 u[X25519::WORDS] {};
-    u32 x1[X25519::WORDS] {};
-    u32 x2[X25519::WORDS] {};
-    u32 z1[X25519::WORDS] {};
-    u32 z2[X25519::WORDS] {};
-    u32 t1[X25519::WORDS] {};
-    u32 t2[X25519::WORDS] {};
+    u32 k[WORDS] {};
+    u32 u[WORDS] {};
+    u32 x1[WORDS] {};
+    u32 x2[WORDS] {};
+    u32 z1[WORDS] {};
+    u32 z2[WORDS] {};
+    u32 t1[WORDS] {};
+    u32 t2[WORDS] {};
 
     // Copy input to internal state
     import_state(k, input_k);
@@ -310,8 +315,8 @@ ErrorOr<ByteBuffer> X25519::compute_coordinate(ReadonlyBytes input_k, ReadonlyBy
 
     // Montgomery ladder
     u32 swap = 0;
-    for (auto i = X25519::BITS - 1; i >= 0; i--) {
-        u32 b = (k[i / X25519::BYTES] >> (i % X25519::BYTES)) & 1;
+    for (auto i = BITS - 1; i >= 0; i--) {
+        u32 b = (k[i / BYTES] >> (i % BYTES)) & 1;
 
         conditional_swap(x1, x2, swap ^ b);
         conditional_swap(z1, z2, swap ^ b);

Userland/Libraries/LibCrypto/Curves/X25519.h

@@ -12,34 +12,12 @@
 namespace Crypto::Curves {
 
 class X25519 : public EllipticCurve {
-
-    static constexpr u8 BITS = 255;
-    static constexpr u8 BYTES = 32;
-    static constexpr u8 WORDS = 8;
-    static constexpr u32 A24 = 121666;
-
 public:
-    size_t key_size() override { return BYTES; }
+    size_t key_size() override { return 32; }
     ErrorOr<ByteBuffer> generate_private_key() override;
     ErrorOr<ByteBuffer> generate_public_key(ReadonlyBytes a) override;
     ErrorOr<ByteBuffer> compute_coordinate(ReadonlyBytes a, ReadonlyBytes b) override;
     ErrorOr<ByteBuffer> derive_premaster_key(ReadonlyBytes shared_point) override;
-
-private:
-    static void import_state(u32* state, ReadonlyBytes data);
-    static ErrorOr<ByteBuffer> export_state(u32* data);
-    static void select(u32* state, u32* a, u32* b, u32 condition);
-    static void set(u32* state, u32 value);
-    static void copy(u32* state, u32* value);
-    static void conditional_swap(u32* first, u32* second, u32 condition);
-    static void modular_multiply_single(u32* state, u32* first, u32 second);
-    static void modular_square(u32* state, u32* value);
-    static void modular_multiply(u32* state, u32* first, u32* second);
-    static void modular_add(u32* state, u32* first, u32* second);
-    static void modular_subtract(u32* state, u32* first, u32* second);
-    static void modular_reduce(u32* state, u32* data);
-    static void to_power_of_2n(u32* state, u32* value, u8 n);
-    static void modular_multiply_inverse(u32* state, u32* value);
 };
 
 }

Userland/Libraries/LibCrypto/Curves/X448.cpp

@@ -11,19 +11,24 @@
 
 namespace Crypto::Curves {
 
-void X448::import_state(u32* state, ReadonlyBytes data)
+static constexpr u16 BITS = 448;
+static constexpr u8 BYTES = 56;
+static constexpr u8 WORDS = 14;
+static constexpr u32 A24 = 39082;
+
+static void import_state(u32* state, ReadonlyBytes data)
 {
-    for (auto i = 0; i < X448::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         u32 value = ByteReader::load32(data.offset_pointer(sizeof(u32) * i));
         state[i] = AK::convert_between_host_and_little_endian(value);
     }
 }
 
-ErrorOr<ByteBuffer> X448::export_state(u32* data)
+static ErrorOr<ByteBuffer> export_state(u32* data)
 {
-    auto buffer = TRY(ByteBuffer::create_uninitialized(X448::BYTES));
+    auto buffer = TRY(ByteBuffer::create_uninitialized(BYTES));
 
-    for (auto i = 0; i < X448::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         u32 value = AK::convert_between_host_and_little_endian(data[i]);
         ByteReader::store(buffer.offset_pointer(sizeof(u32) * i), value);
     }
@@ -31,50 +36,74 @@ ErrorOr<ByteBuffer> X448::export_state(u32* data)
     return buffer;
 }
 
-void X448::select(u32* state, u32* a, u32* b, u32 condition)
+static void select(u32* state, u32* a, u32* b, u32 condition)
 {
     // If B < (2^448 - 2^224 + 1) then R = B, else R = A
     u32 mask = condition - 1;
 
-    for (auto i = 0; i < X448::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         state[i] = (a[i] & mask) | (b[i] & ~mask);
     }
 }
 
-void X448::set(u32* state, u32 value)
+static void set(u32* state, u32 value)
 {
     state[0] = value;
 
-    for (auto i = 1; i < X448::WORDS; i++) {
+    for (auto i = 1; i < WORDS; i++) {
         state[i] = 0;
     }
 }
 
-void X448::copy(u32* state, u32* value)
+static void copy(u32* state, u32* value)
 {
-    for (auto i = 0; i < X448::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         state[i] = value[i];
     }
 }
 
-void X448::conditional_swap(u32* first, u32* second, u32 condition)
+static void conditional_swap(u32* first, u32* second, u32 condition)
 {
     u32 mask = ~condition + 1;
-    for (auto i = 0; i < X448::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         u32 temp = mask & (first[i] ^ second[i]);
         first[i] ^= temp;
         second[i] ^= temp;
     }
 }
 
-void X448::modular_multiply_single(u32* state, u32* first, u32 second)
+static void modular_reduce(u32* state, u32* data, u32 a_high)
+{
+    u64 temp = 1;
+    u32 other[WORDS];
+
+    // Compute B = A - (2^448 - 2^224 - 1)
+    for (auto i = 0; i < WORDS / 2; i++) {
+        temp += data[i];
+        other[i] = temp & 0xFFFFFFFF;
+        temp >>= 32;
+    }
+
+    temp += 1;
+
+    for (auto i = 7; i < WORDS; i++) {
+        temp += data[i];
+        other[i] = temp & 0xFFFFFFFF;
+        temp >>= 32;
+    }
+
+    auto condition = (a_high + (u32)temp - 1) & 1;
+    select(state, other, data, condition);
+}
+
+static void modular_multiply_single(u32* state, u32* first, u32 second)
 {
     // Compute R = (A * B) mod p
     u64 temp = 0;
     u64 carry = 0;
-    u32 output[X448::WORDS];
+    u32 output[WORDS];
 
-    for (auto i = 0; i < X448::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += (u64)first[i] * second;
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
@@ -82,14 +111,14 @@ void X448::modular_multiply_single(u32* state, u32* first, u32 second)
 
     // Fast modular reduction
     carry = temp;
-    for (auto i = 0; i < X448::WORDS / 2; i++) {
+    for (auto i = 0; i < WORDS / 2; i++) {
         temp += output[i];
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
     }
 
     temp += carry;
-    for (auto i = X448::WORDS / 2; i < X448::WORDS; i++) {
+    for (auto i = WORDS / 2; i < WORDS; i++) {
         temp += output[i];
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
@@ -98,22 +127,16 @@ void X448::modular_multiply_single(u32* state, u32* first, u32 second)
     modular_reduce(state, output, (u32)temp);
 }
 
-void X448::modular_square(u32* state, u32* value)
-{
-    // Compute R = (A ^ 2) mod p
-    modular_multiply(state, value, value);
-}
-
-void X448::modular_multiply(u32* state, u32* first, u32* second)
+static void modular_multiply(u32* state, u32* first, u32* second)
 {
     // Compute R = (A * B) mod p
 
     u64 temp = 0;
     u64 carry = 0;
-    u32 output[X448::WORDS * 2];
+    u32 output[WORDS * 2];
 
     // Comba's method
-    for (auto i = 0; i < X448::WORDS * 2; i++) {
+    for (auto i = 0; i < WORDS * 2; i++) {
         if (i < 14) {
             for (auto j = 0; j <= i; j++) {
                 temp += (u64)first[j] * second[i - j];
@@ -121,7 +144,7 @@ void X448::modular_multiply(u32* state, u32* first, u32* second)
                 temp &= 0xFFFFFFFF;
             }
         } else {
-            for (auto j = i - 13; j < X448::WORDS; j++) {
+            for (auto j = i - 13; j < WORDS; j++) {
                 temp += (u64)first[j] * second[i - j];
                 carry += temp >> 32;
                 temp &= 0xFFFFFFFF;
@@ -135,7 +158,7 @@ void X448::modular_multiply(u32* state, u32* first, u32* second)
 
     // Fast modular reduction (first pass)
     temp = 0;
-    for (auto i = 0; i < X448::WORDS / 2; i++) {
+    for (auto i = 0; i < WORDS / 2; i++) {
         temp += output[i];
         temp += output[i + 14];
         temp += output[i + 21];
@@ -143,7 +166,7 @@ void X448::modular_multiply(u32* state, u32* first, u32* second)
         temp >>= 32;
     }
 
-    for (auto i = X448::WORDS / 2; i < X448::WORDS; i++) {
+    for (auto i = WORDS / 2; i < WORDS; i++) {
         temp += output[i];
         temp += output[i + 7];
         temp += output[i + 14];
@@ -154,14 +177,14 @@ void X448::modular_multiply(u32* state, u32* first, u32* second)
 
     // Fast modular reduction (second pass)
     carry = temp;
-    for (auto i = 0; i < X448::WORDS / 2; i++) {
+    for (auto i = 0; i < WORDS / 2; i++) {
         temp += output[i];
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
     }
 
     temp += carry;
-    for (auto i = X448::WORDS / 2; i < X448::WORDS; i++) {
+    for (auto i = WORDS / 2; i < WORDS; i++) {
         temp += output[i];
         output[i] = temp & 0xFFFFFFFF;
         temp >>= 32;
@@ -170,12 +193,18 @@ void X448::modular_multiply(u32* state, u32* first, u32* second)
     modular_reduce(state, output, (u32)temp);
 }
 
-void X448::modular_add(u32* state, u32* first, u32* second)
+static void modular_square(u32* state, u32* value)
+{
+    // Compute R = (A ^ 2) mod p
+    modular_multiply(state, value, value);
+}
+
+static void modular_add(u32* state, u32* first, u32* second)
 {
     u64 temp = 0;
 
     // Compute R = A + B
-    for (auto i = 0; i < X448::WORDS; i++) {
+    for (auto i = 0; i < WORDS; i++) {
         temp += first[i];
         temp += second[i];
         state[i] = temp & 0xFFFFFFFF;
@@ -185,7 +214,7 @@ void X448::modular_add(u32* state, u32* first, u32* second)
     modular_reduce(state, state, (u32)temp);
 }
 
-void X448::modular_subtract(u32* state, u32* first, u32* second)
+static void modular_subtract(u32* state, u32* first, u32* second)
 {
     i64 temp = -1;
 
@@ -211,31 +240,7 @@ void X448::modular_subtract(u32* state, u32* first, u32* second)
     modular_reduce(state, state, (u32)temp);
 }
 
-void X448::modular_reduce(u32* state, u32* data, u32 a_high)
-{
-    u64 temp = 1;
-    u32 other[X448::WORDS];
-
-    // Compute B = A - (2^448 - 2^224 - 1)
-    for (auto i = 0; i < X448::WORDS / 2; i++) {
-        temp += data[i];
-        other[i] = temp & 0xFFFFFFFF;
-        temp >>= 32;
-    }
-
-    temp += 1;
-
-    for (auto i = 7; i < X448::WORDS; i++) {
-        temp += data[i];
-        other[i] = temp & 0xFFFFFFFF;
-        temp >>= 32;
-    }
-
-    auto condition = (a_high + (u32)temp - 1) & 1;
-    select(state, other, data, condition);
-}
-
-void X448::to_power_of_2n(u32* state, u32* value, u8 n)
+static void to_power_of_2n(u32* state, u32* value, u8 n)
 {
     // Compute R = (A ^ (2^n)) mod p
     modular_square(state, value);
@@ -244,11 +249,11 @@ void X448::to_power_of_2n(u32* state, u32* value, u8 n)
     }
 }
 
-void X448::modular_multiply_inverse(u32* state, u32* value)
+static void modular_multiply_inverse(u32* state, u32* value)
 {
     // Compute R = A^-1 mod p
-    u32 u[X448::WORDS];
-    u32 v[X448::WORDS];
+    u32 u[WORDS];
+    u32 v[WORDS];
 
     modular_square(u, value);
     modular_multiply(u, u, value);
@@ -299,14 +304,14 @@ ErrorOr<ByteBuffer> X448::generate_public_key(ReadonlyBytes a)
 // https://datatracker.ietf.org/doc/html/rfc7748#section-5
 ErrorOr<ByteBuffer> X448::compute_coordinate(ReadonlyBytes input_k, ReadonlyBytes input_u)
 {
-    u32 k[X448::WORDS] {};
-    u32 u[X448::WORDS] {};
-    u32 x1[X448::WORDS] {};
-    u32 x2[X448::WORDS] {};
-    u32 z1[X448::WORDS] {};
-    u32 z2[X448::WORDS] {};
-    u32 t1[X448::WORDS] {};
-    u32 t2[X448::WORDS] {};
+    u32 k[WORDS] {};
+    u32 u[WORDS] {};
+    u32 x1[WORDS] {};
+    u32 x2[WORDS] {};
+    u32 z1[WORDS] {};
+    u32 z2[WORDS] {};
+    u32 t1[WORDS] {};
+    u32 t2[WORDS] {};
 
     // Copy input to internal state
     import_state(k, input_k);
@@ -329,7 +334,7 @@ ErrorOr<ByteBuffer> X448::compute_coordinate(ReadonlyBytes input_k, ReadonlyByte
 
     // Montgomery ladder
     u32 swap = 0;
-    for (auto i = X448::BITS - 1; i >= 0; i--) {
+    for (auto i = BITS - 1; i >= 0; i--) {
         u32 b = (k[i / 32] >> (i % 32)) & 1;
 
         conditional_swap(x1, x2, swap ^ b);

Userland/Libraries/LibCrypto/Curves/X448.h

@@ -12,34 +12,12 @@
 namespace Crypto::Curves {
 
 class X448 : public EllipticCurve {
-
-    static constexpr u16 BITS = 448;
-    static constexpr u8 BYTES = 56;
-    static constexpr u8 WORDS = 14;
-    static constexpr u32 A24 = 39082;
-
 public:
-    size_t key_size() override { return BYTES; }
+    size_t key_size() override { return 56; }
     ErrorOr<ByteBuffer> generate_private_key() override;
     ErrorOr<ByteBuffer> generate_public_key(ReadonlyBytes a) override;
     ErrorOr<ByteBuffer> compute_coordinate(ReadonlyBytes a, ReadonlyBytes b) override;
     ErrorOr<ByteBuffer> derive_premaster_key(ReadonlyBytes shared_point) override;
-
-private:
-    static void import_state(u32* state, ReadonlyBytes data);
-    static ErrorOr<ByteBuffer> export_state(u32* data);
-    static void select(u32* state, u32* a, u32* b, u32 condition);
-    static void set(u32* state, u32 value);
-    static void copy(u32* state, u32* value);
-    static void conditional_swap(u32* first, u32* second, u32 condition);
-    static void modular_multiply_single(u32* state, u32* first, u32 second);
-    static void modular_square(u32* state, u32* value);
-    static void modular_multiply(u32* state, u32* first, u32* second);
-    static void modular_add(u32* state, u32* first, u32* second);
-    static void modular_subtract(u32* state, u32* first, u32* second);
-    static void modular_reduce(u32* state, u32* data, u32 data_high);
-    static void to_power_of_2n(u32* state, u32* value, u8 n);
-    static void modular_multiply_inverse(u32* state, u32* value);
 };
 
 }